1. Field of the Invention
Embodiments of the present invention generally relate to database management applications and, more particularly, to a method and apparatus for associating metadata with data.
2. Description of the Related Art
In recent years there has been a tremendous proliferation of databases in many fields of endeavor, ranging from corporate environments and scientific domains to supporting a diverse set of applications on the web. These databases are becoming increasingly complex, both in their internal structure (e.g., thousands of tables) and in their interactions with other databases and applications (e.g., mediators and workflows). There is a consequent need for understanding, maintaining, querying, integrating and evolving these databases. In successfully performing these tasks, metadata information plays an important role. Metadata is any piece of information used to provide a more accurate view of the data and to enable a more efficient processing of it. Examples include schema information, integrity constraints, comments about the data, ontologies, quality parameters, annotations, provenance information, security policies, and statistical data characteristics. Metadata is used in many different fields.
As relational databases proliferate and become increasingly complex, both in their internal structure and in their interactions with other databases and applications, there is a growing need to associate a variety of metadata with the underlying data. Examples include comments, quality parameters, security policies, schema mappings, provenance information, etc. Over the years, numerous proposals have been made for augmenting the data model and the query capabilities of a database in order to facilitate metadata management, typically tailored to deal with specific kinds of metadata. Even though the need has been apparent, a simple, elegant approach to uniformly model and query both data and metadata has been elusive.
Thus, there is a need for a method and apparatus for associating data with metadata.